About this knowledge base
Evinced develops AI-powered digital accessibility testing for developers, QA engineers, and designers. This knowledge base has two goals:
- Explain your test results. Every issue Evinced reports links to an entry that explains what causes it, how it affects people, and how to fix it.
- Share accessibility knowledge. Most entries and articles are useful even if you don't use Evinced, and we hope they contribute to a more inclusive web.
What you'll find here
Web
Accessibility for websites and web applications. Web Validations explain each issue that Evinced's web testing can report, with HTML examples, WCAG techniques, and testing steps. UI Patterns describe how to build common components, such as tabs and modal dialogs, accessibly.
Mobile
Accessibility for native Android and iOS apps. Mobile Validations explain each issue that Evinced's mobile testing can report, with code examples for six frameworks, from XML Views and SwiftUI to Flutter and React Native.
A11y Essentials
Background articles and hands-on guides: who is affected by accessibility issues, how to write accessible code, and how to test with screen readers and voice input. The entries link here when an issue needs more context.
Glossary
Plain-language definitions of the accessibility terms used across the knowledge base.
How to read an entry
Web and mobile entries share the same structure. Each one is named after the rule that reports the issue, such as focus-trap, so you can go straight from a test result to its explanation.
| Section | What it tells you |
|---|---|
| Summary | The requirement in one sentence, at the top of the entry |
| Description | Why the issue matters, who it affects, and how to fix it |
| Pass Patterns and Fail Patterns | Examples of correct and incorrect implementations, usually with code. Mobile entries group them by platform and framework |
| WCAG techniques and ACT Rules | Web only: related W3C techniques and conformance testing rules |
| Try It Yourself | Steps to confirm the issue, for example with a screen reader, the keyboard, or developer tools |
| FAQ | How the issue relates to the standards, why it has its severity level, and other common questions |
| Standards and Regulations | The success criteria and regulations the issue relates to |
| Personas impacted by this issue | The groups of people the issue affects |
| Learn More and Related Issues | Further reading, and entries for similar issues |
Some sections appear only when they apply. For example, an entry has no WCAG techniques section when the W3C doesn't document techniques for its criterion.
Severity levels
Evinced rates every issue by its potential impact on users. Each entry explains its rating in the FAQ, under "Why is this issue marked as…?".
| Severity | What it means |
|---|---|
| Critical | The issue is likely to be a blocker for certain users, such as users of assistive technologies. |
| Serious | The issue will cause some users a poor user experience and, in some cases, even be a blocker. |
| Moderate | The issue will cause a poor user experience for some users. It may make it difficult for them to understand or operate the UI. |
| Minor | The issue will cause an unpleasant user experience for some users. |
Note: These entries describe issues found by automated tests, which can't see the full context of your page or app. The severity therefore reflects the worst-case scenario. In context, an issue may have a lower impact, for example when the same information or function is available in another accessible way.
Standards and regulations
The Standards and Regulations table on each entry lists the requirements the issue relates to:
- WCAG 2.2: the Web Content Accessibility Guidelines, with each success criterion's conformance level (A, AA, or AAA).
- EN 301 549: the European accessibility standard. Clause 9 covers web content, and clause 11 covers software, including mobile apps.
- Section 508: the United States federal accessibility requirements, where they apply.
- Trusted Tester: the Department of Homeland Security test process for Section 508 conformance. It covers web content only.
Some issues aren't tied to a specific success criterion, but still affect the experience of some users. These are classified as Best Practice. They fall outside formal compliance requirements, yet fixing them improves usability and accessibility in practice.
Who is affected
The Personas impacted by this issue box on each entry lists the groups of people the issue can block, such as screen reader users, keyboard users, or people with low vision. To learn how each group uses websites and apps, and what helps them, read Personas.
Feedback
We keep extending and updating this knowledge base. If you can't find what you're looking for, or you spot an error, write to us at knowledge@evinced.com.